﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Utils
{
    public static class FileHelper
    {
        #region Big freaking list of mime types
        private static readonly IDictionary<string, string> _mappings = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase) {
        { ".323", "text/h323" }, { ".svg", "image/svg+xml" }, { ".3g2", "video/3gpp2" }, { ".3gp", "video/3gpp" }, { ".3gp2", "video/3gpp2" }, { ".3gpp", "video/3gpp" }, { ".7z", "application/x-7z-compressed" }, { ".aa", "audio/audible" }, { ".AAC", "audio/aac" }, { ".aaf", "application/octet-stream" }, { ".aax", "audio/vnd.audible.aax" }, { ".ac3", "audio/ac3" }, { ".aca", "application/octet-stream" }, { ".accda", "application/msaccess.addin" }, { ".accdb", "application/msaccess" }, { ".accdc", "application/msaccess.cab" }, { ".accde", "application/msaccess" }, { ".accdr", "application/msaccess.runtime" }, { ".accdt", "application/msaccess" }, { ".accdw", "application/msaccess.webapplication" }, { ".accft", "application/msaccess.ftemplate" }, { ".acx", "application/internet-property-stream" }, { ".AddIn", "text/xml" }, { ".ade", "application/msaccess" }, { ".adobebridge", "application/x-bridge-url" }, { ".adp", "application/msaccess" }, { ".ADT", "audio/vnd.dlna.adts" }, { ".ADTS", "audio/aac" }, { ".afm", "application/octet-stream" }, { ".ai", "application/postscript" }, { ".aif", "audio/x-aiff" }, { ".aifc", "audio/aiff" }, { ".aiff", "audio/aiff" }, { ".air", "application/vnd.adobe.air-application-installer-package+zip" }, { ".amc", "application/x-mpeg" }, { ".application", "application/x-ms-application" }, { ".art", "image/x-jg" }, { ".asa", "application/xml" }, { ".asax", "application/xml" }, { ".ascx", "application/xml" }, { ".asd", "application/octet-stream" }, { ".asf", "video/x-ms-asf" }, { ".ashx", "application/xml" }, { ".asi", "application/octet-stream" }, { ".asm", "text/plain" }, { ".asmx", "application/xml" }, { ".aspx", "application/xml" }, { ".asr", "video/x-ms-asf" }, { ".asx", "video/x-ms-asf" }, { ".atom", "application/atom+xml" }, { ".au", "audio/basic" }, { ".avi", "video/x-msvideo" }, { ".axs", "application/olescript" }, { ".bas", "text/plain" }, { ".bcpio", "application/x-bcpio" }, { ".bin", "application/octet-stream" }, { ".bmp", "image/bmp" }, { ".c", "text/plain" }, { ".cab", "application/octet-stream" }, { ".caf", "audio/x-caf" }, { ".calx", "application/vnd.ms-office.calx" }, { ".cat", "application/vnd.ms-pki.seccat" }, { ".cc", "text/plain" }, { ".cd", "text/plain" }, { ".cdda", "audio/aiff" }, { ".cdf", "application/x-cdf" }, { ".cer", "application/x-x509-ca-cert" }, { ".chm", "application/octet-stream" }, { ".class", "application/x-java-applet" }, { ".clp", "application/x-msclip" }, { ".cmx", "image/x-cmx" }, { ".cnf", "text/plain" }, { ".cod", "image/cis-cod" }, { ".config", "application/xml" }, { ".contact", "text/x-ms-contact" }, { ".coverage", "application/xml" }, { ".cpio", "application/x-cpio" }, { ".cpp", "text/plain" }, { ".crd", "application/x-mscardfile" }, { ".crl", "application/pkix-crl" }, { ".crt", "application/x-x509-ca-cert" }, { ".cs", "text/plain" }, { ".csdproj", "text/plain" }, { ".csh", "application/x-csh" }, { ".csproj", "text/plain" }, { ".css", "text/css" }, { ".csv", "text/csv" }, { ".cur", "application/octet-stream" }, { ".cxx", "text/plain" }, { ".dat", "application/octet-stream" }, { ".datasource", "application/xml" }, { ".dbproj", "text/plain" }, { ".dcr", "application/x-director" }, { ".def", "text/plain" }, { ".deploy", "application/octet-stream" }, { ".der", "application/x-x509-ca-cert" }, { ".dgml", "application/xml" }, { ".dib", "image/bmp" }, { ".dif", "video/x-dv" }, { ".dir", "application/x-director" }, { ".disco", "text/xml" }, { ".dll", "application/x-msdownload" }, { ".dll.config", "text/xml" }, { ".dlm", "text/dlm" }, { ".doc", "application/msword" }, { ".docm", "application/vnd.ms-word.document.macroEnabled.12" }, { ".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document" }, { ".dot", "application/msword" }, { ".dotm", "application/vnd.ms-word.template.macroEnabled.12" }, { ".dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template" }, { ".dsp", "application/octet-stream" }, { ".dsw", "text/plain" }, { ".dtd", "text/xml" }, { ".dtsConfig", "text/xml" }, { ".dv", "video/x-dv" }, { ".dvi", "application/x-dvi" }, { ".dwf", "drawing/x-dwf" }, { ".dwp", "application/octet-stream" }, { ".dxr", "application/x-director" }, { ".eml", "message/rfc822" }, { ".emz", "application/octet-stream" }, { ".eot", "application/octet-stream" }, { ".eps", "application/postscript" }, { ".etl", "application/etl" }, { ".etx", "text/x-setext" }, { ".evy", "application/envoy" }, { ".exe", "application/octet-stream" }, { ".exe.config", "text/xml" }, { ".fdf", "application/vnd.fdf" }, { ".fif", "application/fractals" }, { ".filters", "Application/xml" }, { ".fla", "application/octet-stream" }, { ".flr", "x-world/x-vrml" }, { ".flv", "video/x-flv" }, { ".fsscript", "application/fsharp-script" }, { ".fsx", "application/fsharp-script" }, { ".generictest", "application/xml" }, { ".gif", "image/gif" }, { ".group", "text/x-ms-group" }, { ".gsm", "audio/x-gsm" }, { ".gtar", "application/x-gtar" }, { ".gz", "application/x-gzip" }, { ".h", "text/plain" }, { ".hdf", "application/x-hdf" }, { ".hdml", "text/x-hdml" }, { ".hhc", "application/x-oleobject" }, { ".hhk", "application/octet-stream" }, { ".hhp", "application/octet-stream" }, { ".hlp", "application/winhlp" }, { ".hpp", "text/plain" }, { ".hqx", "application/mac-binhex40" }, { ".hta", "application/hta" }, { ".htc", "text/x-component" }, { ".htm", "text/html" }, { ".html", "text/html" }, { ".htt", "text/webviewhtml" }, { ".hxa", "application/xml" }, { ".hxc", "application/xml" }, { ".hxd", "application/octet-stream" }, { ".hxe", "application/xml" }, { ".hxf", "application/xml" }, { ".hxh", "application/octet-stream" }, { ".hxi", "application/octet-stream" }, { ".hxk", "application/xml" }, { ".hxq", "application/octet-stream" }, { ".hxr", "application/octet-stream" }, { ".hxs", "application/octet-stream" }, { ".hxt", "text/html" }, { ".hxv", "application/xml" }, { ".hxw", "application/octet-stream" }, { ".hxx", "text/plain" }, { ".i", "text/plain" }, { ".ico", "image/x-icon" }, { ".ics", "application/octet-stream" }, { ".idl", "text/plain" }, { ".ief", "image/ief" }, { ".iii", "application/x-iphone" }, { ".inc", "text/plain" }, { ".inf", "application/octet-stream" }, { ".inl", "text/plain" }, { ".ins", "application/x-internet-signup" }, { ".ipa", "application/x-itunes-ipa" }, { ".ipg", "application/x-itunes-ipg" }, { ".ipproj", "text/plain" }, { ".ipsw", "application/x-itunes-ipsw" }, { ".iqy", "text/x-ms-iqy" }, { ".isp", "application/x-internet-signup" }, { ".ite", "application/x-itunes-ite" }, { ".itlp", "application/x-itunes-itlp" }, { ".itms", "application/x-itunes-itms" }, { ".itpc", "application/x-itunes-itpc" }, { ".IVF", "video/x-ivf" }, { ".jar", "application/java-archive" }, { ".java", "application/octet-stream" }, { ".jck", "application/liquidmotion" }, { ".jcz", "application/liquidmotion" }, { ".jfif", "image/pjpeg" }, { ".jnlp", "application/x-java-jnlp-file" }, { ".jpb", "application/octet-stream" }, { ".jpeg", "image/jpeg" }, { ".jpg", "image/jpg" }, { ".js", "application/x-javascript" }, { ".jsx", "text/jscript" }, { ".jsxbin", "text/plain" }, { ".latex", "application/x-latex" }, { ".library-ms", "application/windows-library+xml" }, { ".lit", "application/x-ms-reader" }, { ".loadtest", "application/xml" }, { ".lpk", "application/octet-stream" }, { ".lsf", "video/x-la-asf" }, { ".lst", "text/plain" }, { ".lsx", "video/x-la-asf" }, { ".lzh", "application/octet-stream" }, { ".m13", "application/x-msmediaview" }, { ".m14", "application/x-msmediaview" }, { ".m1v", "video/mpeg" }, { ".m2t", "video/vnd.dlna.mpeg-tts" }, { ".m2ts", "video/vnd.dlna.mpeg-tts" }, { ".m2v", "video/mpeg" }, { ".m3u", "audio/x-mpegurl" }, { ".m3u8", "audio/x-mpegurl" }, { ".m4a", "audio/m4a" }, { ".m4b", "audio/m4b" }, { ".m4p", "audio/m4p" }, { ".m4r", "audio/x-m4r" }, { ".m4v", "video/x-m4v" }, { ".mac", "image/x-macpaint" }, { ".mak", "text/plain" }, { ".man", "application/x-troff-man" }, { ".manifest", "application/x-ms-manifest" }, { ".map", "text/plain" }, { ".master", "application/xml" }, { ".mda", "application/msaccess" }, { ".mdb", "application/x-msaccess" }, { ".mde", "application/msaccess" }, { ".mdp", "application/octet-stream" }, { ".me", "application/x-troff-me" }, { ".mfp", "application/x-shockwave-flash" }, { ".mht", "message/rfc822" }, { ".mhtml", "message/rfc822" }, { ".mid", "audio/mid" }, { ".midi", "audio/mid" }, { ".mix", "application/octet-stream" }, { ".mk", "text/plain" }, { ".mmf", "application/x-smaf" }, { ".mno", "text/xml" }, { ".mny", "application/x-msmoney" }, { ".mod", "video/mpeg" }, { ".mov", "video/quicktime" }, { ".movie", "video/x-sgi-movie" }, { ".mp2", "video/mpeg" }, { ".mp2v", "video/mpeg" }, { ".mp3", "audio/mpeg" }, { ".mp4", "video/mp4" }, { ".mp4v", "video/mp4" }, { ".mpa", "video/mpeg" }, { ".mpe", "video/mpeg" }, { ".mpeg", "video/mpeg" }, { ".mpf", "application/vnd.ms-mediapackage" }, { ".mpg", "video/mpeg" }, { ".mpp", "application/vnd.ms-project" }, { ".mpv2", "video/mpeg" }, { ".mqv", "video/quicktime" }, { ".ms", "application/x-troff-ms" }, { ".msi", "application/octet-stream" }, { ".mso", "application/octet-stream" }, { ".mts", "video/vnd.dlna.mpeg-tts" }, { ".mtx", "application/xml" }, { ".mvb", "application/x-msmediaview" }, { ".mvc", "application/x-miva-compiled" }, { ".mxp", "application/x-mmxp" }, { ".nc", "application/x-netcdf" }, { ".nsc", "video/x-ms-asf" }, { ".nws", "message/rfc822" }, { ".ocx", "application/octet-stream" }, { ".oda", "application/oda" }, { ".odc", "text/x-ms-odc" }, { ".odh", "text/plain" }, { ".odl", "text/plain" }, { ".odp", "application/vnd.oasis.opendocument.presentation" }, { ".ods", "application/oleobject" }, { ".odt", "application/vnd.oasis.opendocument.text" }, { ".one", "application/onenote" }, { ".onea", "application/onenote" }, { ".onepkg", "application/onenote" }, { ".onetmp", "application/onenote" }, { ".onetoc", "application/onenote" }, { ".onetoc2", "application/onenote" }, { ".orderedtest", "application/xml" }, { ".osdx", "application/opensearchdescription+xml" }, { ".p10", "application/pkcs10" }, { ".p12", "application/x-pkcs12" }, { ".p7b", "application/x-pkcs7-certificates" }, { ".p7c", "application/pkcs7-mime" }, { ".p7m", "application/pkcs7-mime" }, { ".p7r", "application/x-pkcs7-certreqresp" }, { ".p7s", "application/pkcs7-signature" }, { ".pbm", "image/x-portable-bitmap" }, { ".pcast", "application/x-podcast" }, { ".pct", "image/pict" }, { ".pcx", "application/octet-stream" }, { ".pcz", "application/octet-stream" }, { ".pdf", "application/pdf" }, { ".pfb", "application/octet-stream" }, { ".pfm", "application/octet-stream" }, { ".pfx", "application/x-pkcs12" }, { ".pgm", "image/x-portable-graymap" }, { ".pic", "image/pict" }, { ".pict", "image/pict" }, { ".pkgdef", "text/plain" }, { ".pkgundef", "text/plain" }, { ".pko", "application/vnd.ms-pki.pko" }, { ".pls", "audio/scpls" }, { ".pma", "application/x-perfmon" }, { ".pmc", "application/x-perfmon" }, { ".pml", "application/x-perfmon" }, { ".pmr", "application/x-perfmon" }, { ".pmw", "application/x-perfmon" }, { ".png", "image/png" }, { ".pnm", "image/x-portable-anymap" }, { ".pnt", "image/x-macpaint" }, { ".pntg", "image/x-macpaint" }, { ".pnz", "image/png" }, { ".pot", "application/vnd.ms-powerpoint" }, { ".potm", "application/vnd.ms-powerpoint.template.macroEnabled.12" }, { ".potx", "application/vnd.openxmlformats-officedocument.presentationml.template" }, { ".ppa", "application/vnd.ms-powerpoint" }, { ".ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12" }, { ".ppm", "image/x-portable-pixmap" }, { ".pps", "application/vnd.ms-powerpoint" }, { ".ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12" }, { ".ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow" }, { ".ppt", "application/vnd.ms-powerpoint" }, { ".pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12" }, { ".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation" }, { ".prf", "application/pics-rules" }, { ".prm", "application/octet-stream" }, { ".prx", "application/octet-stream" }, { ".ps", "application/postscript" }, { ".psc1", "application/PowerShell" }, { ".psd", "application/octet-stream" }, { ".psess", "application/xml" }, { ".psm", "application/octet-stream" }, { ".psp", "application/octet-stream" }, { ".pub", "application/x-mspublisher" }, { ".pwz", "application/vnd.ms-powerpoint" }, { ".qht", "text/x-html-insertion" }, { ".qhtm", "text/x-html-insertion" }, { ".qt", "video/quicktime" }, { ".qti", "image/x-quicktime" }, { ".qtif", "image/x-quicktime" }, { ".qtl", "application/x-quicktimeplayer" }, { ".qxd", "application/octet-stream" }, { ".ra", "audio/x-pn-realaudio" }, { ".ram", "audio/x-pn-realaudio" }, { ".rar", "application/octet-stream" }, { ".ras", "image/x-cmu-raster" }, { ".rat", "application/rat-file" }, { ".rc", "text/plain" }, { ".rc2", "text/plain" }, { ".rct", "text/plain" }, { ".rdlc", "application/xml" }, { ".resx", "application/xml" }, { ".rf", "image/vnd.rn-realflash" }, { ".rgb", "image/x-rgb" }, { ".rgs", "text/plain" }, { ".rm", "application/vnd.rn-realmedia" }, { ".rmi", "audio/mid" }, { ".rmp", "application/vnd.rn-rn_music_package" }, { ".roff", "application/x-troff" }, { ".rpm", "audio/x-pn-realaudio-plugin" }, { ".rqy", "text/x-ms-rqy" }, { ".rtf", "application/rtf" }, { ".rtx", "text/richtext" }, { ".ruleset", "application/xml" }, { ".s", "text/plain" }, { ".safariextz", "application/x-safari-safariextz" }, { ".scd", "application/x-msschedule" }, { ".sct", "text/scriptlet" }, { ".sd2", "audio/x-sd2" }, { ".sdp", "application/sdp" }, { ".sea", "application/octet-stream" }, { ".searchConnector-ms", "application/windows-search-connector+xml" }, { ".setpay", "application/set-payment-initiation" }, { ".setreg", "application/set-registration-initiation" }, { ".settings", "application/xml" }, { ".sgimb", "application/x-sgimb" }, { ".sgml", "text/sgml" }, { ".sh", "application/x-sh" }, { ".shar", "application/x-shar" }, { ".shtml", "text/html" }, { ".sit", "application/x-stuffit" }, { ".sitemap", "application/xml" }, { ".skin", "application/xml" }, { ".sldm", "application/vnd.ms-powerpoint.slide.macroEnabled.12" }, { ".sldx", "application/vnd.openxmlformats-officedocument.presentationml.slide" }, { ".slk", "application/vnd.ms-excel" }, { ".sln", "text/plain" }, { ".slupkg-ms", "application/x-ms-license" }, { ".smd", "audio/x-smd" }, { ".smi", "application/octet-stream" }, { ".smx", "audio/x-smd" }, { ".smz", "audio/x-smd" }, { ".snd", "audio/basic" }, { ".snippet", "application/xml" }, { ".snp", "application/octet-stream" }, { ".sol", "text/plain" }, { ".sor", "text/plain" }, { ".spc", "application/x-pkcs7-certificates" }, { ".spl", "application/futuresplash" }, { ".src", "application/x-wais-source" }, { ".srf", "text/plain" }, { ".SSISDeploymentManifest", "text/xml" }, { ".ssm", "application/streamingmedia" }, { ".sst", "application/vnd.ms-pki.certstore" }, { ".stl", "application/vnd.ms-pki.stl" }, { ".sv4cpio", "application/x-sv4cpio" }, { ".sv4crc", "application/x-sv4crc" }, { ".svc", "application/xml" }, { ".swf", "application/x-shockwave-flash" }, { ".t", "application/x-troff" }, { ".tar", "application/x-tar" }, { ".tcl", "application/x-tcl" }, { ".testrunconfig", "application/xml" }, { ".testsettings", "application/xml" }, { ".tex", "application/x-tex" }, { ".texi", "application/x-texinfo" }, { ".texinfo", "application/x-texinfo" }, { ".tgz", "application/x-compressed" }, { ".thmx", "application/vnd.ms-officetheme" }, { ".thn", "application/octet-stream" }, { ".tif", "image/tiff" }, { ".tiff", "image/tiff" }, { ".tlh", "text/plain" }, { ".tli", "text/plain" }, { ".toc", "application/octet-stream" }, { ".tr", "application/x-troff" }, { ".trm", "application/x-msterminal" }, { ".trx", "application/xml" }, { ".ts", "video/vnd.dlna.mpeg-tts" }, { ".tsv", "text/tab-separated-values" }, { ".ttf", "application/octet-stream" }, { ".tts", "video/vnd.dlna.mpeg-tts" }, { ".txt", "text/plain" }, { ".u32", "application/octet-stream" }, { ".uls", "text/iuls" }, { ".user", "text/plain" }, { ".ustar", "application/x-ustar" }, { ".vb", "text/plain" }, { ".vbdproj", "text/plain" }, { ".vbk", "video/mpeg" }, { ".vbproj", "text/plain" }, { ".vbs", "text/vbscript" }, { ".vcf", "text/x-vcard" }, { ".vcproj", "Application/xml" }, { ".vcs", "text/plain" }, { ".vcxproj", "Application/xml" }, { ".vddproj", "text/plain" }, { ".vdp", "text/plain" }, { ".vdproj", "text/plain" }, { ".vdx", "application/vnd.ms-visio.viewer" }, { ".vml", "text/xml" }, { ".vscontent", "application/xml" }, { ".vsct", "text/xml" }, { ".vsd", "application/vnd.visio" }, { ".vsi", "application/ms-vsi" }, { ".vsix", "application/vsix" }, { ".vsixlangpack", "text/xml" }, { ".vsixmanifest", "text/xml" }, { ".vsmdi", "application/xml" }, { ".vspscc", "text/plain" }, { ".vss", "application/vnd.visio" }, { ".vsscc", "text/plain" }, { ".vssettings", "text/xml" }, { ".vssscc", "text/plain" }, { ".vst", "application/vnd.visio" }, { ".vstemplate", "text/xml" }, { ".vsto", "application/x-ms-vsto" }, { ".vsw", "application/vnd.visio" }, { ".vsx", "application/vnd.visio" }, { ".vtx", "application/vnd.visio" }, { ".wav", "audio/wav" }, { ".wave", "audio/wav" }, { ".wax", "audio/x-ms-wax" }, { ".wbk", "application/msword" }, { ".wbmp", "image/vnd.wap.wbmp" }, { ".wcm", "application/vnd.ms-works" }, { ".wdb", "application/vnd.ms-works" }, { ".wdp", "image/vnd.ms-photo" }, { ".webarchive", "application/x-safari-webarchive" }, { ".webtest", "application/xml" }, { ".wiq", "application/xml" }, { ".wiz", "application/msword" }, { ".wks", "application/vnd.ms-works" }, { ".WLMP", "application/wlmoviemaker" }, { ".wlpginstall", "application/x-wlpg-detect" }, { ".wlpginstall3", "application/x-wlpg3-detect" }, { ".wm", "video/x-ms-wm" }, { ".wma", "audio/x-ms-wma" }, { ".wmd", "application/x-ms-wmd" }, { ".wmf", "application/x-msmetafile" }, { ".wml", "text/vnd.wap.wml" }, { ".wmlc", "application/vnd.wap.wmlc" }, { ".wmls", "text/vnd.wap.wmlscript" }, { ".wmlsc", "application/vnd.wap.wmlscriptc" }, { ".wmp", "video/x-ms-wmp" }, { ".wmv", "video/x-ms-wmv" }, { ".wmx", "video/x-ms-wmx" }, { ".wmz", "application/x-ms-wmz" }, { ".wpl", "application/vnd.ms-wpl" }, { ".wps", "application/vnd.ms-works" }, { ".wri", "application/x-mswrite" }, { ".wrl", "x-world/x-vrml" }, { ".wrz", "x-world/x-vrml" }, { ".wsc", "text/scriptlet" }, { ".wsdl", "text/xml" }, { ".wvx", "video/x-ms-wvx" }, { ".x", "application/directx" }, { ".xaf", "x-world/x-vrml" }, { ".xaml", "application/xaml+xml" }, { ".xap", "application/x-silverlight-app" }, { ".xbap", "application/x-ms-xbap" }, { ".xbm", "image/x-xbitmap" }, { ".xdr", "text/plain" }, { ".xht", "application/xhtml+xml" }, { ".xhtml", "application/xhtml+xml" }, { ".xla", "application/vnd.ms-excel" }, { ".xlam", "application/vnd.ms-excel.addin.macroEnabled.12" }, { ".xlc", "application/vnd.ms-excel" }, { ".xld", "application/vnd.ms-excel" }, { ".xlk", "application/vnd.ms-excel" }, { ".xll", "application/vnd.ms-excel" }, { ".xlm", "application/vnd.ms-excel" }, { ".xls", "application/vnd.ms-excel" }, { ".xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12" }, { ".xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12" }, { ".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" }, { ".xlt", "application/vnd.ms-excel" }, { ".xltm", "application/vnd.ms-excel.template.macroEnabled.12" }, { ".xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template" }, { ".xlw", "application/vnd.ms-excel" }, { ".xml", "text/xml" }, { ".xmta", "application/xml" }, { ".xof", "x-world/x-vrml" }, { ".XOML", "text/plain" }, { ".xpm", "image/x-xpixmap" }, { ".xps", "application/vnd.ms-xpsdocument" }, { ".xrm-ms", "text/xml" }, { ".xsc", "application/xml" }, { ".xsd", "text/xml" }, { ".xsf", "text/xml" }, { ".xsl", "text/xml" }, { ".xslt", "text/xml" }, { ".xsn", "application/octet-stream" }, { ".xss", "application/xml" }, { ".xtp", "application/octet-stream" }, { ".xwd", "image/x-xwindowdump" }, { ".z", "application/x-compress" }, { ".zip", "application/x-zip-compressed" } };
        #endregion

        static string[] AllowContentType
        {
            get
            {
                return new string[] { "image/*", "video/*", "audio/*", "application/*" };
            }
        }

        public static string GetMimeType(string extension)
        {
            if (extension == null)
            {
                throw new ArgumentNullException("extension");
            }
            if (!extension.StartsWith("."))
            {
                extension = "." + extension;
            }
            return _mappings.TryGetValue(extension, out string mime) ? mime : "application/octet-stream";
        }

        public static string GetExtension(string mimeType)
        {
            if (mimeType == null)
            {
                throw new ArgumentNullException("mimeType");
            }
            foreach (var item in _mappings)
            {
                if (item.Value.Equals(mimeType))
                {
                    return item.Key;
                }
            }
            return "";
        }
        /// <summary>
        /// 是否允许上传
        /// </summary>
        /// <param name="contentType"></param>
        /// <returns></returns>
        public static bool IsAllow(string contentType)
        {
            if (contentType == null)
                throw new ArgumentNullException("contentType");
            foreach (var item in AllowContentType)
            {
                if (Regex.IsMatch(contentType.ToLower(), item))
                {
                    return true;
                }
            }
            return false;
        }

        /// <summary>
        /// 重命名
        /// </summary>
        /// <param name="oldName"></param>
        /// <param name="newName"></param>
        /// <returns></returns>
        public static string ReName(string oldName, string newName)
        {
            var ext = Path.GetExtension(oldName);
            return Path.GetFileNameWithoutExtension(newName) + ext;
        }

        /// <summary>
        /// 重命名
        /// </summary>
        /// <param name="oldName"></param>
        /// <returns></returns>
        public static string ReName(string oldName)
        {
            return StringHelper.RadomFileName() + Path.GetExtension(oldName);
        }

        public static bool Exists(string fileName, params string[] paths)
        {
            string path = Path.Combine(paths);
            return File.Exists(Path.Combine(path, fileName));
        }
        public static bool Exists(string fileName, out string pathName, params string[] paths)
        {
            string path = Path.Combine(paths);
            pathName = Path.Combine(path, fileName.TrimStart('/'));
            return File.Exists(pathName);
        }

        public static async Task SaveAsync(this Stream stream, string fileName, params string[] paths)
        {
            string path = Path.Combine(paths);
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
            using FileStream fileStream = new FileStream(Path.Combine(path, fileName), FileMode.Create);
            await stream.CopyToAsync(fileStream);
        }

        public static void Save(this Stream stream, string fileName, params string[] paths)
        {
            string path = Path.Combine(paths);
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
            using FileStream fileStream = new FileStream(Path.Combine(path, fileName), FileMode.Create);
            stream.CopyTo(fileStream);
        }
    }

}
